Synergistic insecticidal compositions



United States Patent SYNERGISTIC INSECTICIDAL COMPOSITIUNS Howard A. Jones and John A. Garman, Baltimore, Md.,

and Berton C. Dickinson, Lyndonville, N.Y., assignors to Food Machinery and Chemical (Iorporation, New

York, N.Y., a corporation of Delaware No Drawing. Original application Mar. 24, 1955 Ser.

No. 496,596. Divided and this application Oct. 23,

1958, Ser. No. 769,068

5 Claims.

This invention relates broadly to insecticidal compositions, and more particularly to insecticidal compositions containing an organic carbamate acid derivative and 0,0-dimethyl S-(1,2-dicarbeth0xyethyl) dithiophosphate, hereinafter referred to as Malathion. More particularly, this invention relates to synergistic insecticidal compositions of these compounds wherein the insecticidal effectiveness of each component is enhanced by the presegce of the other to produce an unexpected combined e ect.

When two or more substances in combination show an unexpectedly high activity, as for instance, insecticidal activity, the resulting phenomenon is called synergism. The mechanism of synergism is by no means understood. It is, in fact, quite probable that it difiers with different synergistic combinations. The term synergism can be defined, however, as a cooperative action which is encountered in combinations of two or more biological-1y active components in which the combined activity of the two components exceeds the sum of the activities of the components when used alone. The insecticidal activity of the mixed components cannot be predicted from known values of the individual components, but is unpredictable and depends on the individual activity of neither.

It is an object of this invention to provide insecticidal compositions of enhanced killing power. Another object of this invention is to produce novel compositions containing compounds capabeof synergizing the knockdown and killing properties of individual toxicants. A further object of this invention is to provide compositions including a relatively toxic phosphorus containing insecticide in which superior insecticidal activity is obtained because of the synergistic elfects, but in which the ultimate toxicity to warm-blooded animals is greatly reduced because of the lower concentrations of the phosphorous compounds required when used in combination with the relatively less toxic carbamates. Other objects and advantages of the invention will become apparent from the description of the invention set forth below.

According to this invention there are provided synergistic insecticidal compositions comprising 0,0-dimethyl S (l,2-dicarbeth0xyethyl) dithiophosphate, hereinafter called Malathion, and an organic carbamate ester having the following general formula:

NCOOR wherein R is selected from the group consisting of phenyl and furfuryl radicals and R is selected from the group of benzyl, trichloroethyl and Z-ethylhexyl radicals. These carbamates may be prepared as described in c0- pending application Serial No. 812,113 filed May 11, 1959.

The synergistic insecticidal compositions of this invention may be used on a wide variety of insect and mite species, but are particularly effective against such insects as the two-spotted spider mite and the Mexican bean beetle. The combinations are highly effective and 2,990,316 Patented June 27, 1961 quirements as the control of truck crop, forage crop and orchard insects.

The synergistic compositions of this invention can be formulated as aqueous emulsions, as dry or wettable powders, as solutions or in any other suitable vehicle. The insecticidal compositions can be utilized as sprays, as :dusts, as aerosol mixtures, insecticidal coating compositions, and as residues. In general, they can be applied by methods commonly used for control or eradication of insects, mites and the like. Thus these insecticidal compositions can be formulated with solvents, diluents and carrier media, adhesives, spreading, wetting and emulsifying agents and other ingredients.

The relative proportions of the active ingredients as well as inert carriers, solvents, dispersants and the like may vary within wide limits.

Thus the relative proportion (ratio) of the Malathion to the carbamate ester can range from 20 parts of the former per 1 part of the latter to 1 pant of the former per 40 parts of the latter and preferably about l part of the former to about 2 parts of the latter.

The quantities of the component toxicants in the final insecticidal compositions can range from 0.01% to 25.00% for the Malathion and from 0.05% to 50.00% for the carbamate, and preferably from 0.10% to 10.00% for the Malathion and from 0.10% to 25.00% for the carbamate.

The procedures of the testing methods are described below. The details of the test experiments including the type of formulation and mode of application or dosing, and the species of insects which served as test subjects are given in the examples.

Insects used in the testing included the house fly (Musca domestica L.), Mexican bean beetle (Epilachna varivest is Muls.), pea aphid (Macrosiphum pisi, [Kltbr] two-spotted spider mite ('Tetranychus bimaculatus Harvey), harlequin bug (Murgantia histrionica [Hahn]) and squash :bug (Anasa tristis).

The test methods used are described as follows:

Dust tower method This general method is described in the following reference, Moore, J. Econ. But. 43, No. 2, 18 8-190 (1950).

'The dusting apparatus consists of a vertical glass cylinder, 34 inches high and 8.5 inches in diameter, into which the appropriate dust sample is discharged through a small hole in the center of the cover, by means of a 7 small laboratory duster operating at air pressure of economical to use for such large-scale insecticidal re- 40 p.s.i.g. The duster assembly comprises a 10 ml. beaker, into which the weighed sample is placed, and fitted with a rubber stopper through which pass the air inlet and dust outlet tubes, both of which are made of /4 inch diameter copper tubing. At the outer end of the air inlet tube is a trigger valve that serves as a control 7 for dispensing the dust. The inner end of this tube reaches nearly to the bottom of the beaker. The end of it is sealed but, along the sides, seven 0.032 inch holes are drilled at irregular intervals which serve as air inlets. Such an arrangement causes pronounced turbulence of the dust and thus insures exhausting the complete sample :from the beaker. The dust outlet tube forms an arch from the top of the beaker to the top of the glass dusting tower.

After discharge of the sample into the tower, there is allowed a 2-minute settling time before removal of foliage or insects being treated. A weighed metal plate is placed in the tower each time a test is made, and by weighing the amount of dust deposited on it, it is then possible to calculate the amount applied per acre.

Because of day-to-day variations in the results obtained by this test method, comparisons among the individual components and their combinations were made 3 simultaneously in order to minimize this source ation.

Slight modifications in this test employed for specific 'insect species are as noted below. a

of variwherein R is selected from the group consisting of phenyl and furfuryl radicals and R is selected from the group of benzyl, trichloroethyl and 2-ethylhexyl radicals, wherein said components are present in the ratio of about Mexican bean beetle-In tests using this insect, the 2 parts of said carbamate per partof said dithiophosbean foilage was dusted then infested with fourth instar phate.

Mexican bean beetle larvae, These were allowed to feed 2. Synergistic insecticidal compositions comprising 0, for 24 hours, then treated foliage was replaced with'un- O-dimethyl S(1,2-dicarbethoxyethyl)dithiophosphate and treated. Mortality records were made at 48 hours; 7 trichloroethyl N-phenyl carbamate, said components Two-spottedspider mite.In tests on two-spotted mites, 10 being present in the ratio of about 2 parts of said carthe mites were confined to the upper surfaces of potted bamate ester to about 1 part of said dithiophosphate. bean'plants by a Tanglefoot ring. The bean plants 3. Synergistic insecticidal compositions comprising were placed in the glass tower and the mites direct- 0,0 dimethyl S (1,2 dicarbethoxyethyl)dithiophosdusted. -Mortality readings were taken in 24 hours. phate and benzyl N-phenylcarbamate, said components Only adult mites were used in determining mortality being present in the ratio of about 2 parts of said counts. carbamate ester to about 1 part of said dithiophosphate.

Squash bug-For this test squash leaves were collect- 4. Synergistic insecticidal compositions comprising ed in the field and the cut ends of the stem were wrapped 0,0 dimethyl S (1,2 dicacrbethoxyethyl)dithiophosin moist cotton. Individual leaves were "then placed in phate and 2-ethylhexyl N-furfuryl car'bamate, said com- 3.5 inch Petri dishes and dusted as described above. ponents being present in the'ratio of about 2 parts of Each treated leaf was then infested with 10 last instar said carbamate ester to about 1 part of said dithiophossquash bng nymphs and the covers of the Petri dishes phate. were replaced. At the end of 24 hours the treated leaves 5. The method of killing insects which comprises apwere removed and fresh untreated leaves were introduced plying to the insects and their habitat a synergistic ininto the dishes. Mortality counts were taken after the 25 secticidal composition comprising 0,0-dimethyl S-(l,2- bugs had been ou the untreated leaves for 24 hours. 5

Table 1 Nc0om H Oarbamate Phosphate Rate i Mortalit Dust Dust (lbsJ Test Method Test Subject (percent R R Cone. Name Cone. acre) (pe (percent) cent) PhenyL, Benzyl 1 a 32.7 Dust Tower.-. Mexican BeanBeetle 0 Malathion 0.5 25.9 on on D0 d0 1 d0-.. 0.6 28.3 do 90 Do. Tri0hl0roethy1. 1 9. 3 Two-Spotted Spider Mite.. O Malathlon 0. 5 s. 0 .....do 59 Do do 1 .do 0.5 8.3 fin 90 Ethyl. 1-Naphthyl 9.1 do 8 0.25 13.7 n 34 Do do; 0.25 10.5 on 100 Do 2-Naphthy1 51.4 Squash Bug 0 Malathion 0. 25 46. 2 do 0 Do 0 0.5 do 0.25 45.6 on 90 Furfuryl... Benzyl 0.5, 22.0 Two-spotted spider Mite 2 Malathion 0. 25 25. 5 .....d5 Do do 0.5 ..-do.-.-- 0.25 19.5 --do 100 Ethyl 2-Ethylhexyl 1.0 5 25-9 Squash Bug 10 Malathion 0.25 40.0 do 0 Do do 1.0 do 0.5 27.5 do Furtury do 0. 5 16. 8 Two-spotted Spider Mite. 2 Malathion 0. 25 25. 4 do 41 Do do 0.5 do-.- 0.25 19.3 r1n 87 Do'.'. 2-(1-Chlor'o- 0.5 23.3 on 4 pwpYD- Malathion 0.25 25.4 do do 41 135...... .do 0.5 do- 0.25 21.7 5 (in tin 77 PhenyL.-- TrichloroethyL. 1.0 47.6 do Squash Bug 0 Malathion 0.5 51.9 do do 0 Do do-. 1.0 do 0.6 45.6, do do 90 The results of the data summarized in Table 1 demon- 60 dicarbethoxyethyl)dithiophosphate and an organic carstrate the marked synergism of'the insecticidal composibamate having the general formula: tions of this inventionon a number of insects.

This application is a division of copending application 4 Serial No. 496,596 filed March 24, 1955, now abandoned, 0 0B which is a continuation-in-part of Serial No. 427,374, 5 filed .May 3, 1954, now abandoned. H

We claim:

l. Synergistic insecticidal compositions comprising wherein R is selected from the group consisting of phenyl 0,0 dimethyl S (1,2 dicarbethoxyethyl)dithiophosand furfuryl radicals and R is selected from the group phate and an organic carbamate ester having the follow- 7 consisting of benzyl, tn'chloroethyl and Z-ethylhexyl radiing general formula: cals, wherein said components are present in the ratio of about two parts of said carbamate per part of said dithiophosphate. /NCOOB 7 I i i 76 "(References -on'following page) S References Cited in the file of this patent Chemical Age, vol. 63, No. 1 631 (1950), p. 540.

UNITED STATES PATENTS 1 harp: Agr. News Letter, January-February 1952, pp. 2,503,390 lelirfek P 11, Roark: us. Dept. Agr. Bulletin, E-344 (May 1935 2,679,508 Gysm May 25, 1954 5 2E6.

OTHER REFERENCES Frear: Chemistry of the Pesticides, 3rd ed., January King: U.S.D.A Handbook No. '69, May 1-954, pp. 73-91- 105-108.

. UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,990,316 June 27, I961 Howard A. Jones et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read. as I corrected below...

Column 1, line 38, for capabe" read capable column 3, lines .28 29 and 30, the formula should appear as shown below instead of as in the patent: 4

wcooa H Signed and sealed this 21st day of November 1961.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Commissioner of Patents Attesting Officer U SCO M M DC 

5. THE METHOD OF KILLING INSECTS WHICH COMPRISES APPLYING TO THE INSECTS AND THEIR HABITAT A SYNERGISTIC INSECTIDAL COMPOSITION COMPRISING O,O-DIMETHYL S-(1,2DICARBETHOXYETHYL) DITHIOPHOSPHATE AND AN ORGANIC CARBAMATE HAVING THE GENERAL FORMULA: 